A 77-100 GHz power amplifier using 0.1-μm GaAs PHEMT technology

A wideband MMIC power amplifier at W-band is reported in this letter. The four-stage MMIC, developed using 0.1 μm GaAs pseudomorphic HEMT (PHEMT) technology, demonstrated a flat small signal gain of 12:4 ± 2 dB with a minimum saturated output power (Psat) of 14.2 dBm from 77 to 100 GHz. The typical Psat is better by 16.3 dBm with a flatness of 0.4 dB and the maximum power added efficiency is 6% between 77 and 92 GHz. This result shows that the amplifier delivers output power density of about 470 mW/mm with a total gate output periphery of 100 μm. As far as we know, it is nearly the best power density performance ever published from a single ended GaAs-based PHEMT MMIC at this frequency band.